Voice over Internet Protocol (VoIP) is an alternative to circuit-committed protocols such as Time Division Multiplexing (TDM) that are used on conventional Public Switched Telephone Networks (PSTN's). With VoIP, voice communications share the same network with data, effectively consolidating bandwidth by sending packets to any available path at any given time. Monitoring and managing a VoIP network requires a network protocol to communicate with, and gather information from, numerous Internet Protocol (IP) network devices.
FIG. 1 is a block diagram of a functional architecture of a communications network, according to the prior art. As shown in FIG. 1, a network management system 105 is coupled to managed devices 110, 115, 120, and 125 via links 130, 135, 140, and 145, respectively. In general, the managed devices may be routers, switches, call servers, gateways, gatekeepers, handsets, Multipoint Control Units (MCU's), Session Initiation Protocol (SIP) proxy servers, or other devices. As illustrated, links 130, 135, 140, and 145 utilize Simple Network Management Protocol (SNMP).
SNMP has many disadvantages, however. For example, SNMP is limited to five management commands: “get” to request values from the Management Information Base (MIB) of a managed device; “get next” to request the successive values from the MIB; “get response” to retrieve the answer returned; “set” to update MIB values; and “trap” to send an event notification. Moreover, SNMP information is presented in long unstructured data strings. The limited command set and unwieldy data formats associated with SNMP result in increased cost and cycle time for the development and maintenance of IP network management systems. Moreover, the processing overhead for SNMP-based network management systems may be substantial, making them unsuitable for VoIP and other network communications that must operate in near real-time with low packet losses. A more robust management protocol is needed for time-sensitive IP network applications.